Sketchup to Blender: aligning multiple objects to a grid
I don't use sketch up.  So don't bother reading this if you allready know how to center an object. But if you are brand new to Blender. I know that it can be impossible to learn the basic functions so here I wrote the instructions and give a link to a really good tutorial that will help with the basics on object manipulation; url is at the bottom.

Here are two different ways to go about moving your object to center:


Use the cntrl alt shift c, function. pressing these four buttons will bring up a menu titled "Set Origin". First select the option "origin to 3d cursor".  Next place your 3d cursor on your grid where you like ( the little red and white target symbol that goes wherever you click ). Press cntrl alt shift c again. This time select " geometry to origin". This way is useful for resetting your object geometry for use with modifiers such as mirror modifier, and may be just the thing for the problem at hand. Again I don't use sketch up so I hope I am not wasting your time here


Tips and Pointer for cntrl alt shift c:

*make sure you are in object mode

*make sure you have active object chosen in your outliner panel.


on your transform panel go to the bottom and manually center your 3d cursor by typing 0.00, 0.00, 0.00 into the three boxes for 3d cursor location x, y, and Z. 


The more simple way might work ...


The other way is to use your transform toggle hot;key N. With your transform panel open there will be location data for your active object at the top. On the x, y and z axis. If you simply type 0.00, 0.00, 0.00 into each of these boxes x,y, and z. That should bring your object to center more easily. 


tips and pointers:


You might try applying transform 


https://wiki.blender.org/index.php/User:Fade/Doc:2.6/Manual/3D_interaction/Transform_Control/Reset_Object_Transformations

have you seen this stack exchange entry? a user named GM writes about converting files. You may have probably converted your skp to a blend file? in which case, my answer is probably enough allready. 
Import SketchUp &quot;.skp&quot; files

here is the turorial I like for manipulating objects:

https://www.youtube.com/watch?v=gmQKZydrYY8&amp;feature=youtu.be